OP4 file format description

Many people share .op4 files without attaching instructions on how to use it. Yet it isn’t evident for everyone which program a .op4 file can be edited, converted or printed with. On this page, we try to provide assistance for handling .op4 files.

1 filename extension(s) found in our database.

.op2 - Nastran Binary Results

The OP2 data files are related to MSC Nastran. The OP2 file is a Nastran Binary Results (OUTPUT2). MSC Nastran is a powerful, highly flexible analysis and optimisation finite-element program on an open architecture for analysing stress, vibration, and heat transfer characteristics of structures and mechanical components.

MSC Nastran
Data files
- / -
Nastran Binary Results related extensions:
Expert Definition Language Document
P-CAD Database
Cesium Vector 3D Tiles Data
RVS-COM Prepaid SMS Package
HEC-HMS Control Specifications Data
BlackBerry Encrypted 3GP

Naturally, other applications may also use the .op4 file extension. Even harmful programs can create .op4 files. Be especially cautious with .op4 files coming from an unknown source!

Can't open a .op4 file?

When you double-click a file to open it, Windows examines the filename extension. If Windows recognizes the filename extension, it opens the file in the program that is associated with that filename extension. When Windows does not recognize a filename extension, you receive the following message:

Windows can't open this file:


To open this file, Windows needs to know what program you want to use to open it. Windows can go online to look it up automatically, or you can manually select one from a list of programs that are installed on your computer.

To avoid this error, you need to set the file association correctly.

The .op4 file extension is often given incorrectly!

According to the searches on our site, these misspellings were the most common in the past year:

lp4, op, ope, opr, opt, p4, po4, pp4

Is it possible that the filename extension is misspelled?

Similar file extensions in our database:

Microsoft Visual Studio Workspace Options
ProWorx NXT List Module Option File
Concordance Native Viewer Database
µVision Project Options Data
Altair FEKO CADFEKO Optimisation Data
Digital Line Graph Optional Vector Data

Operating systems

DataTypes.net currently supports the following operating systems:

Windows XP/Vista, Windows 7/8/10, Windows 11, CentOS, Debian GNU/Linux, Ubuntu Linux, FreeBSD, macOS, Mac OS X, iOS, Android

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DataTypes.net >> OP4 file